1. Field of the Invention
The invention relates generally to apparatus for both generating and storing energy through the use of cryogenic fluid as a working fluid. More particularly, the invention pertains to a closed loop heat sink engine, which produces power utilizing low boiling point fluids heated by atmospheric heat or other available heat such as waste heat from a conventional electrical power plant. Additionally, the invention pertains to a heat sink engine capable of storing surplus energy in the form of liquified gas during off-peak production periods, in which the liquified gas is later utilized to produce electrical power during peak or high demand periods.
2. Description of the Prior Art
Electrical power generation plants utilize a number of different energy sources including nuclear, hydroelectric, solar, wind, and fossil fuels. In most regions of the world, fossil fuel power plants relying upon internal or external combustion engines, are still the most common. In such power plants, the combustion of coal or oil is used to increase the energy of a working fluid, such as air or water vapor. Then, the heated working fluid is utilized to drive a turbine and an electrical generator. Finally, the unused heat of the working fluid is transferred to a heat sink, such as the atmosphere.
It is well recognized that fossil fuel driven power plants emit airborne pollutants from the combustion exhaust gases, and increase the temperature of the surrounding atmosphere from the heat rejection. Given modern society's dependence on increasingly large amounts of electrical power, there is an existing need to generate and store electrical power with minimal use of conventional fossil fuel plants so as to lessen the adverse impact they have on the environment.
The general concept of using low molecular weight or low-boiling point fluids for power generation and power storage is appealing. Combustion and heat discharge to the atmosphere would be eliminated. In an ideal system, the diurnal excursions of atmospheric temperature could drive a system and produce electrical power. The design goal for such a system contemplates that the Tlow component be lowered in order to increase the Carnot efficiency η of a power plant (η=(Thigh−Tlow)/Thigh). However, the technical requirements to condense a gas, having a critical temperature which is well below ambient temperature, or to compress a low molecular weight gas such as helium or hydrogen, have deterred commercial applications.